. Comparative morphology and biology of the fungi, mycetozoa and bacteria. Fungi -- Morphology; Bacteria -- Morphology. CHAPTER V. — COMPARATIVE REVIEW.—UREDINEAE, 279 Section LXXX. In the second and much most common case the germ-tube of the aecidiospores does not become a promycelium, but forces its way by acropetal growth through a stoma into the interior of the host, and there developes directly into a mycelium. The mycelium ultimately forms gonidia on distinct hymenia and always by acrogenous abjunction ; and the gonidia, which can germinate either directly or after a period of rest, deve
. Comparative morphology and biology of the fungi, mycetozoa and bacteria. Fungi -- Morphology; Bacteria -- Morphology. CHAPTER V. — COMPARATIVE REVIEW.—UREDINEAE, 279 Section LXXX. In the second and much most common case the germ-tube of the aecidiospores does not become a promycelium, but forces its way by acropetal growth through a stoma into the interior of the host, and there developes directly into a mycelium. The mycelium ultimately forms gonidia on distinct hymenia and always by acrogenous abjunction ; and the gonidia, which can germinate either directly or after a period of rest, develope a promycelium with sporidia like that of Endophyllum. The sporidia are usually obliquely ovoid like those of Endophyllum, but in some species are round. The germ-tube of the sporidia when it has penetrated into the host gives rise to a new mycelium producing spermogonia and aecidia. These gonidia which form promycelia have been named tcleutospores (Fig. 124 //, III, Fig. 128 A, and Fig. 129). The species which produce aecidiospores and teleutospores are again dis- tinguished into two subordinate groups according to the stages in the course of the development. In some the stages of the development in the order of then- appearance are mycelium, aecidium, teleutospore, promycelium, sporidium, and there are no others. This is the case in G-ymnosporangium, Puccinia section Hemi- puceinia, as for instance in P. Falcariae. In other species the mycelium formed from the aecidiospore produces other gonidia besides the teleuto- spores, which are called uredosporcs (Tulasne's stylospores). These too arise by acrogenous abjunction (Fig. 124 III, nr), and as regards the time of their development they may be said to be always the precursors of the associated teleuto- spores. They are formed according to the species either in the same hymenia as the teleutospores, or apart from them in special ones which are simply styled uredo or uredo-layer. Being short-lived they are able to germin
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